Figure 2.

Effect of bombesin on secretion of catecholamines from cultured bovine adrenal chromaffin cells. (A) Cells were incubated with (0.33, 3.3 or 33 μM) or without (none) indicated concentrations of bombesin for up to 120 min at 37°C. Subsequently, both catecholamines secreted spontaneously in the incubation medium were measured by HPLC. Data represent the mean ± SEM. (B) Cells treated with (Bombesin) or without (none) 3.3 μM bombesin for 30 min were washed twice with normal medium, and incubated with medium at 37°C in the absence or presence of 100 μM nicotine for 5 min. Subsequently, catecholamines secreted in the incubation medium were measured. Basal values obtained at 37°C without nicotine were not changed by bombesin treatment, and were thus subtracted. Data represent the mean ± SEM.